Problem description:

Hello my name is Seoconero and I am helping with the maps of a game. My problems are:
-When the owner of the game copy and paste my work to the current game, all the icons which size is over 32*32 became 32*32 and most of them are 256*256.
So anyone has an idea of how to solve this problem?
Are you using a "map maker" of sorts? In other words, is the core of your work environment different than what the live game uses?

I'm asking because this issue sounds like your project environment is using the default, modern TOPDOWN_MAP world.map_format, while the live game is using the deprecated TILED_ICON_MAP format.

TOPDOWN_MAP allows icons to be used in their native size without any hassle. On the other hand, TILED_ICON_MAP requires big icons (anything larger than world.icon_size) to be added in pieces, where attempting to use them as big icons results in the icon being shrunken/condensed to fit a single tile.

You just being the map designer, I don't expect you to have access to the source code, so this may be something you'll have to relay to your partner.
Additionally, when you copy and paste icons into the icon editor, it will split them up into sections equal to the size of the current icons in the DMI file. DMI files expect every frame to have the same dimensions across the entire file.
Thank you very much guys